A method for selectively leaching and separating vanadium and iron from stone coal vanadium ore

Abstract

The invention provides a method for selectively leaching and separating vanadium and iron from stone coal vanadium ore. and the first leaching slag; adding a reducing agent after the obtained first leachate is recycled, and after the reaction is cooled and crystallized to recover the ferrous salt; the obtained first leaching slag is mixed with concentrated sulfuric acid and then matured to obtain a clinker; the obtained The slag is added with water for secondary leaching, and the second leaching solution and the second leaching residue are obtained by solid-liquid separation. The method adopts a two-stage leaching process to selectively leaching iron and vanadium, which prevents a large amount of impurity elements such as iron in the stone coal vanadium ore from entering the vanadium-containing solution from the source, reduces the concentration of impurity ions in the vanadium-containing leaching solution, and improves the subsequent content of the leaching solution. The purification efficiency of the vanadium solution; the method is simple to operate, does not require roasting, is environmentally friendly, has less acid consumption, lower cost and higher economic benefits.

Description

technical field [0001] The invention belongs to the technical field of nonferrous metal extraction, and relates to a method for selectively leaching and separating vanadium and iron from stone coal vanadium ore. Background technique [0002] Stone coal vanadium ore is an important vanadium resource with abundant reserves, and the vanadium contained therein (expressed as V 2 o 5 Count) up to 1.18×10 8 t, accounting for about 87% of the national vanadium reserves. According to the degree of weathering, stone coal can be divided into oxidized stone coal vanadium ore and primary stone coal vanadium ore. Vanadium in oxidized stone coal vanadium ore exists in the form of tetravalent vanadium or pentavalent vanadium, which is in the free state of oxides. , so it is easy to extract by acid leaching; while the vanadium in primary stone coal vanadium ore exists in the lattice structure of aluminosilicate in the form of trivalent vanadium, which has strong stability and is difficult...

AI Technical Summary

Problems solved by technology

However, ion exchange is usually used to treat leachate containing pentavalent vanadium, and the pH of the leachate is required to be not lower than 2.0 for better ion exchange. However, when the pH of the leachate reaches above 1.5, it can slowly precipitate vanadium-containing precipitates, resulting in vanadium loss

The solvent extraction method is suitable for vanadium-containing leaching solution with many impurities and high acidity. CN 103695643A discloses a method for extracting vanadium pentoxide from stone coal vanadium ore mixed with acid heap ore. In the method, the stone coal vanadium ore is crushed and mixed with acid Deposit, stockpile mines are leached with clean water, the leachate and leaching slag filtered by the pulp, the leachate is neutralized by lime and soda ash, then extracted with the extractant, back-extracted with sulfuric acid, and then prepared from the back-extraction liquid through a series of operations to prepare vanadium pentoxide, but While this method realizes the separation of vanadium and iron and the enrichment of vanadium, a small part of iron and vanadium will still be co-extracted, which will affect the quality of subsequent vanadium products.

The chemical precipitation method refers to the selective oxidation of iron in the leachate to ferric iron by selecting a suitable oxidant under certain conditions, and then the separation of vanadium and iron is achieved by chemical precipitation, but the selective oxidation of iron is difficult to accurately control , often resulting in higher vanadium loss

[0005] In addition, in order to improve the incomplete separation of vanadium and iron in the vanadium-containing leaching solution and the high loss of vanadium, CN106755959A discloses a method for the two-stage selective leaching of stone coal to separate vanadium and iron. Roasting in an oxidative atmosphere to obtain a roasted material, the roasted material was pickled with sulfuric acid solution I and sulfuric acid solution II to obtain iron-containing leachate and vanadium-containing leachate, but the roasting temperature (800-900°C) of this method is relatively high, which increases the Its energy consumption, sulfur, nitrogen and other elements contained in stone coal will generate sulfur and nitrogen-containing polluting gases during the roasting process, and the leaching rate of vanadium still needs to be improved

Images